Method for making pile structures with concrete casings



L. MULLER Feb. 2, 1960 METHOD FOR MAKING PILE STRUCTURES WITH CONCRETE CASINGS Original Filed July 12, 1955 United States Patent -METHOD FOR MAKING PlLE STRUCTURES WITH CONCRETE CASINGS Ludwi Muller, Marburg (Lahn), Germany Original application July 12, 1955, Serial No. 521,571. Divided and this application October 2, 1956, Serial No. 613,559

Claims priority, application Germany October 7, 1955 '3 Claims. (CI. 61-57) The present invention relates to the making of piles with concrete casings, in which a pile comprising a hollow shaft and a wedge-shaped foot secured to the lower end of the shaft is rammed into soil and the hollow space formed around the foot is filled-in with concrete under pressure As the concrete rises in the hollow space, the soil surrounding the space is compressed by the high pressure of the concrete, the hollow space being unevenly enlarged due to the varying resistance of the soil strata through which the pile is passing. Piles rammed into soil as described have a remarkable load-carrying capacity and high stress resistance, because, in addition to the pile shaft, the concrete casing with its different cross-section has likewise a load-carrying function while at the same time anchoring the pile securely in the building site.

The present invention is a further development of the above-mentioned pile arrangement, adapting it more particularly to humid soil.

This application is a division of my application Serial No. 521,571 filed July 12, 1955.

According to the invention, cement or concrete in a condition to be poured is fed under low pressure to the hollow space for filling it in, the space being sealed toward the end of the ramming process, whereupon concrete is forced-in under higher pressure.

There are some soils, in which the hollow space formed by ramming-in a pile, closes-in due to a yielding of marshy or muddy soil, so that the hollow space will shrink due to vibrations as the ramming proceeds; in some cases the hollow space may be filled-in completely. This cannot happen when, according to the invention, the hollow space is at once filled in by the cement or concrete emerging at the lower end of the pile shaft; this prevents the space from becoming filled with ground water or soil.

The invention will now be more fully described with reference to the accompanying drawing, but it should be understood that this is given by way of illustration and not of limitation and that many changes in the details can be made without departing from the spirit of the invention.

In the drawing:

Fig. 1 illustrates the driven-in pile in elevation with the surrounding concrete in sectionf Fig. 2 is an enlarged view of the pile in longitudinal section, showing the lower portion of the pile with hollow space filled in;

Fig. 3 is a section along IlIIII of Fig. 2;

Fig. 4 is a section along IV-IV of Fig. 2; and

Fig. 5 is a longitudinal section through another embodiment of the pile head.

Referring now to the drawing, a hollow pile-shaft 61 is shown, having a wedge-shaped hollow foot 62 secured thereto. The foot is open toward the top and its cross section is larger than that of the pile-shaft. To the foot 62, a flat chisel 63 is attached in the extension of the shaft axis; the chisel projects beyond the foot and lies 2,923,133 Patented Feb. 2, 1960 with its blunt edge against the end of the shaft. In order to secure the foot 62 on the pile shaft 61, metal pieces 64 are provided, which are welded to shaft 61 and to the walls of foot 62. As shown in the embodiment illustrated in the drawing, outlets 65 may be provided in the lower end of shaft 61; however, such openings may be dispensed with.

At the top, shaft 61 bears a head plate 66 which closes the shaft. Below the plate, there is an opening 67 in the shaft for attachment of a sleeve 68 to which a supply tube 69 for concrete can be connected. Near the upper end of the shaft 61 a cone-shaped packing member 70 is arranged, which can be made detachable; in that case, the Packing member may be removed a few hours after the pile has been driven in, so that it is available for other piles.

When the pile shaft is driven into a building site, the foot 62 digs out a hollow space 71 in the soil. In accordance with the present invention, while the ramming proceeds, grout or a thin mixture of concrete is fed under light pressure through tube 69 and sleeve 68 into pile 61 and pile foot 62. From foot 62, which is open at the top, the forced-in grout or thin concrete mixture emerges and rises in the hollow space 71, dug out by foot 62. In this manner, the hollow space is continuously filled with cement or concrete. This proceeds, until at the end of the ramming the packing member 70 enters the soil and closes off the then filled-in space 71 toward the top. The cement or concrete will then only rise up the member 70. While the pile is driven in and concrete is forced down, care is taken that the level of concrete remains closely below the surface of the building site.

As soon as the pile has been driven down to the desired depth and the hollow space 71 made by foot 62 has been filled-in by cement or concrete under low pres sure, and after the hollow space with its filling has been sealed-off at the top, the pressure, under which cement or concrete is forced down, is considerably increased. The concrete thus admitted has a pasty or gritty quality. As compression of the soil surrounding the original hollow space 71 proceeds, the final concrete casing 73 (Fig. 1) is produced.

Fig. 5 illustrates a different embodiment of the head plate, which in this case consists of a block-shaped member 74 closing the upper end of pile-shaft 61. Member 74 has an angular bore 75 with the sleeve 68 attached to the horizontal branch of the bore.

Instead of using a hollow pile-shaft, as illustrated, I may also use a solid shaft. In this case, grout or a thin mixture of concrete is admitted to foot 62 by means of one or several feed pipes at the outside of the pile-shaft.

What I claim is:

1. A method of making a pile structure wherein a pile-- shaft is encased in a cementitious material, said method comprising ramming into the soil a pile-shaft mounting adjacent to its upper end a collar and at its lower end a foot having a peripheral outline wider than the peripheral outline of the pile-shaft, said foot forming a clearance in the soil surrounding the pile-shaft as said pile-shaft is rammed into the soil, simultaneously with the ramming of the pile-shaft into the soil feeding a cementitious material to the lower ml of the pile-shaft and into the clearance formed by the foot whereby the clearance is continually filled with the cementitious material as it is formed, ramming the pile-shaft until it reaches a depth at which the collar reaches approximately ground level whereby the collar closes the clearance at its upper end, and finally forcing additional cementitious material into the now closed clearance whereby the cementitious material encasing the pile-shaft penetrates into the soil surrounding the pile-shaft.

2. A method of making a pile structure wherein a pileshaft is encased ina cementitious material, said method comprising ramming into the soil a hollow pile-shaft mounting adjacent to its upper end a collar and at its lower end a foot open at its top and having a peripheral outline wider than the peripheral outline of the pile-shaft, said foot forming a clearance in the soil surrounding the pile-shaft as said pile-shaft is rammed into the soil, simultaneously with the ramming of the pile-shaft into the soil feeding a cementitious material through said hollow pileshaft to the lower end thereof and, through the open end of the foot, into the clearance formed by the foot whereby the clearance is continually filled with the cementitious material as it is formed, ramming the pile-shaft until its reaches a depth at which the collar reaches approximately ground level whereby the collar closes the clearance at its upper end, and finally forcing additional cementitious material into the now closed clearance whereby the cementitious material encasing the pile-shaft penetrates into the soil surrounding the pile-shaft.

3. The method according to claim 1 wherein said is a thin mixture of concrete and wherein said additional cementitious material is a concrete mixture of gritty consistency.

References Cited in the file of this patent UNITED STATES PATENTS 1,101,662 Ridley June 30, 1914 1,189,108 Hildebrand June 27, 1916 1,591,165 Hesse July 6, 1926 2,146,645 Newman Feb. 7, 1939 FOREIGN PATENTS 490,153 France Nov. 29, 1918 280,292 Italy Dec. 4, 1930 

